BOSTON (AP) — The average pay for America's private university presidents grew by 10.5% in 2017, with dozens receiving more than $1 million and three topping the $5 million mark, according to an annual survey by The Chronicle of Higher Education.

The survey, released Tuesday, finds that private university presidents at more than 500 schools averaged $608,000 in total annual compensation, including salary, bonuses, benefits and other perks. Their average pay increased by 4% in 2016 and by 9% in the previous year.

The two top earners in 2017 both came from schools in Rhode Island. Ronald K. Machtley, of Bryant University, received $6.28 million, while John J. Bowen, of Johnson & Wales University, received $5.3 million. Bowen retired at the end of 2018, and Machtley has announced he will retire later this year.

Although both presidents earn base salaries under $1 million, their total pay was inflated by deferred compensation deals that came to fruition in 2017, The Chronicle found. Under such deals, colleges set aside money each year to be paid to their chiefs at a future date. Deferred compensation has becoming common at U.S. colleges as a way to discourage leaders from taking jobs elsewhere.

A statement from Bryant University says Machtley has "transformed Bryant from a regional college to a leading university in its field."

"At 24 years, President Machtley has served nearly quadruple the 6.5 year average tenure of a university president," the school said. "Since President Machtley is one of the longest serving university presidents in the nation, it's not surprising that the 2017 payment of his long-term compensation pushed him to the top."

Bryant enrolls about 3,800 students in Smithfield, Rhode Island.

Officials at Johnson & Wales University said Bowen's pay package was established 18 years ago and later updated to reflect his accomplishments and years of service. James H. Hance Jr., chairman of the school's Board of Trustees, said Bowen started as a faculty member and worked his way up to chancellor over decades at the university.

"During his 45 years at JWU, the university experienced growth in both enrollment and new facilities while successfully achieving many of the goals set forth in its strategic plans," Hance said in a statement.

Behind Machtley and Bowen were Shirley Ann Jackson of New York's Rensselaer Polytechnic Institute, who received $5.2 million; Amy Gutmann of the University of Pennsylvania, with $2.9 million; and Ronald Daniels, of Johns Hopkins University, with $2.7 million.

Officials at Rensselaer, Penn and Johns Hopkins did not immediately respond to requests for comment.

The survey found that 64 private university presidents made more than $1 million in 2017, up from 61 the year before. The number of executives topping $2 million grew, too, from eight to 11. For many of the top earners, salaries accounted for less than half of their overall pay, while the rest came from bonuses and other perks.

The Chronicle's survey is based on university tax filings for 2017, the latest year available. It includes yearly salaries, along with a variety of other forms of compensation including health insurance, housing and retirement benefits.

In a separate survey in July, The Chronicle found that public university chiefs were paid an average of $484,000 in 2018, an increase of about 10% over the year before. Seventeen public university presidents made $1 million or more in 2018, compared with a dozen the year before.